Answer to Question #143452 in General Chemistry for Aida

Question

Calculate the potential of the following concentration cell at 25.0 ◦C.

Ag | Ag+(1.00×10−3 M) || Ag+(0.100 M) | Ag

Identify the anode and the cathode in the cell. How would the cell potential change if the concentrations
of Ag+ in both half-cells were doubled? Use the Nernst equation to support your answer.

Answer 1

Ag | Ag+(1.00×10−3 M) || Ag+(0.100 M) | Ag

concentration cell at 25.0 ◦C.

An electrochemical cell of this type, in which the anode and cathode compartments are identical except for the concentration of a reactant, is called a concentration cell. As the reaction proceeds, the difference between the concentrations of Ag+ in the two compartments will decrease, as will Ecell.

2Ag⁺_(aq) +2e^- > 2Ag_(s)

Cu_(s) > Cu²⁺_(aq) + 2e^-

E^o reduction = +0.799v

E^o Oxidation = - 0.518v

2Ag⁺_(aq) + Al_(s) > 2Ag_(s) + Cu²⁺_(aq) E^O =+0.281v

N = 2 moles of electrons

E^o_cell = (0.0592/n) log K

0.281 = (0.0592/2) log K

Log k = 9.49

K = 10^9.49 =3.1 x 10⁹